Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
The Availability Calendar WordPress plugin before 1.2.1 does not escape the category attribute from its shortcode before using it in a SQL statement, leading to a SQL Injection issue, which can be exploited by any user able to add shortcode to posts/pages, such as contributor+
CWE-89 - SQL Injection
Structured Query Language (SQL) injection attacks are one of the most common types of vulnerabilities. They exploit weaknesses in vulnerable applications to gain unauthorized access to backend databases. This often occurs when an attacker enters unexpected SQL syntax in an input field. The resulting SQL statement behaves in the background in an unintended manner, which allows the possibility of unauthorized data retrieval, data modification, execution of database administration operations, and execution of commands on the operating system.